CycleKarts GB

Forums => Tech Forum => Topic started by: TheGiantTribble on 09 Sep 22, 09:31 am

Title: Front suspension
Post by: TheGiantTribble on 09 Sep 22, 09:31 am
Good morning all.

Looking at the inspiration car, it has twin trailing arms as it's front suspension, now how in the heck do I do that easily???
Let me emphasis the easily bit!!!
Any one know of an old light weight car I could rob, or can think of an simples way of achieving this?
Preferably using no more than scraps of plywood, empty sweet wrappers, and the change found down the back of the sofa!!!
Title: Re: Front suspension
Post by: Jimr1999 on 09 Sep 22, 11:05 am
Are they not twin a frame torsion bars in the front end? https://www.motorsportmagazine.com/archive/article/march-1990/37/maserati-v8-ri-part-three

... ALfa Cyclekart vid... https://www.youtube.com/watch?v=lC-8ewUnhg8

... Torsion bar out of 3/8" socket extension ... https://www.youtube.com/watch?v=hAMQDjyAJCg&t=2s
Title: Re: Front suspension
Post by: TheGiantTribble on 10 Sep 22, 10:06 am
Interesting, very interesting...a socket extension!

Thanks for those ideas.
Title: Re: Front suspension
Post by: synthpunk on 12 Sep 22, 05:07 pm
Whilst messing about designing my rubber rear suspension for my kart,I came across the Tucker 48/ Tucker Torpedo, which used rubber in torsion and rubber in shear for its rear and front suspension respectively. Once Iíve got my kart all squared away for this year and back on its wheels (itís currently being painted) Iím thinking of having a play with making a modular, bolt on front independent suspension system based on the Tuckers front suspension, using Volvo transmission mounts as the shear rubber. Basically itís a big rubber block sandwiched between the upper and lower control arms.
Title: Re: Front suspension
Post by: TheGiantTribble on 15 Sep 22, 08:53 am
Tuckers front suspension...never come across that before, thanks for the info.
Title: Re: Front suspension
Post by: StefanN on 16 Sep 22, 03:22 pm
Intriguing Bill, what inspiration car are you thinking of building?
Title: Re: Front suspension
Post by: Chris L on 17 Sep 22, 10:55 am
Are they not twin a frame torsion bars in the front end? https://www.motorsportmagazine.com/archive/article/march-1990/37/maserati-v8-ri-part-three

... ALfa Cyclekart vid... https://www.youtube.com/watch?v=lC-8ewUnhg8

... Torsion bar out of 3/8" socket extension ... https://www.youtube.com/watch?v=hAMQDjyAJCg&t=2s
Note to Builders; This type of Double wishbone / "A" Arm Independent suspension set up is not within CKGB  Rules and Guidelines, more suited to Post War Race cars of the Colin Chapman era.   Please see section 3 and read the Rationale 3.5.  Builders are asked to follow the Pre war inspiration car for type of suspension.
Title: Re: Front suspension
Post by: Jimr1999 on 17 Sep 22, 01:00 pm
Sorry Chris, my bad I should have payed more attention to the rules. I was just looking at Bills profile and it had a Maserati V8R1 as inspiration car, which I believe had torsion bar suspension not dissimilar to the old 1930's Citroen traction avant hence the torsion bar links. I think the set up in the second video actually has a solid front axle mounted to the torsion bars via drop links in his future videos.
If you need the post removing I will gladly.
Jim
Title: Re: Front suspension
Post by: TheGiantTribble on 19 Sep 22, 10:18 am
Ok, Ok, lets try and answer some questions

Stef...the inspiration car is a 1938 ERA 'E' type GP1.
Sorry to Jim for any confusion, the Maserati is as finished as it's ever going to be, admittedly in a few pieces at the moment.
The reason for the original enquiry is, as anyone who has had a go in my Masser knows, the pedals are in a shall we say 'unique' position, however they make Xan sit too low, if I change them to suit him, I can't get in it let alone drive it. Can't make the pedal position adjustable because of a reinforcing bar in what is now the wrong place...it seemed like a good idea at the time...DOH!
So Xan and I have decided to build a new CK, one to suit both of us, with pedals that are adjustable, thanks to a  car seat adjusting mechanism I have going spare. My first attempt at building a CK was GP1 so seems a good time to go back and give her another go.

The GP1 has twin trailing arms front suspension, a unusual arraignment worthy of copying if easy to achieve with my meager/none existent skills.





Title: Re: Front suspension
Post by: Jimr1999 on 19 Sep 22, 10:41 am
That would make it torsion bars in the transverse position from a quick google
 "Front suspension was by trailing links and transverse torsion bars."
The trick would be a solid mounting in the front middle of the chassis to take 4 matched socket extensions to the trailing arms, A bushed mount to the outside of the chassis on each side, adjusters in between the middle mount, a king pin through an upright connecting each pair of trailing arms and a set of Gemini spindle carriers?

Way from orthodox, but in keeping with the original. Also a lot of head scratching to make sure it can't come to bits under load or flex too much with side load.
Probably best to simplify this  ;D
Title: Re: Front suspension
Post by: TheGiantTribble on 19 Sep 22, 10:59 am
Probably best to simplify this  ;D

Hang on a second, you'll be suggesting I go all sensible next...Bahhhhh humbug, never going to happen, not on my watch, I mean where's the fun in that!!!  ;D ;D ;D
Title: Re: Front suspension
Post by: Jimr1999 on 19 Sep 22, 11:38 am
Essentially one side would look a bit like this...
Title: Re: Front suspension
Post by: synthpunk on 02 Oct 22, 09:43 am
Iíve been thinking about what comes next once Iíve finished the White Riley. Iíd like to learn to weld so something that requires some fabrication practise would be ace. So Iíve become somewhat enamoured with the 1936 Alta GP. Itís drop dead sexy, has great history, comes from the Correct Era and also apparently has independent front suspension thatís right up my alley- double wishbones and rubber blocks in compression as the springing elements. Ace. Ive so far managed to find a grand total of zero pictures of how they did it, but Iíve thought of several ways I could do it so it looks right on the outside at leastÖ.
Title: Re: Front suspension
Post by: StefanN on 02 Oct 22, 10:23 am
So Iíve become somewhat enamoured with the 1936 Alta GP. Itís drop dead sexy, has great history, comes from the Correct Era and also apparently has independent front suspension thatís right up my alley- double wishbones and rubber blocks in compression as the springing elements. Ace. Ive so far managed to find a grand total of zero pictures of how they did it, but Iíve thought of several ways I could do it so it looks right on the outside at leastÖ.

Lovely looking car.  Maybe sliders and pillars based on this article https://www.motorsportmagazine.com/archive/article/may-1981/52/alta

Looks like thereís one at Brooklands too
https://www.brooklandsmuseum.com/explore/heritage-and-collection/our-collection/alta-voiturette